The objectives of this study are: 1) to determine the optimal efficacious dose at which Trocade when administered against background therapy of MTX, a NSAID and corticosteroid (if required) prevents structural damage to articular joints; 2) to determine if Trocade when administered against background therapy can improve or stablize clinical signs and symptoms, disability or quality of life; 3) to determine the safety of Trocade when administered against background therapy of MTX and/or NSAID and/or steroids; 4) to investigate the pharmacokinetics of Trocade when administered against background therapy.